A product manager spent months working in dental practices to bring AI to small businesses. Then a16z led its $35 million round

The founder spent months working in dental practices, then personally set up the first 100 customers. Customers told investors its greatest value was recovering revenue they had been missing.

By a16z News08-01 · 12 min read⚑ Expert view · personal take
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The one-minute version
  • Before a16z invested $35 million in the company, its founder spent months working in dental practices. His daily job was manually entering hundreds of insurance payments into their systems.
  • Half of all AI agent activity is software engineering. Healthcare accounts for just 1%. That number is easy to misread.
  • What customers valued most was not quite what the founder had pitched.
⚑ This article was written by Lassie co-founder Steijn Pelle and published by a16z on the same day a16z announced that it had led Lassie's $35 million Series A. Customer counts, time savings, and performance claims all come from the company or its investor and have not been independently verified. Our additional explanations of the mechanics, industry data, and limitations are sourced in the article.
How it began

A product manager went to work in dental practices

On June 3, 2026, a16z announced that it had led a $35 million Series A in Lassie. The same day, it published the founder's account in its own outlet. The funding is not the real story. What makes this unusual is the level of operating detail: 700 US dental practices across 49 states and more than $10 million in annualized revenue. It also lays out, with unusual specificity, how to break into a vertical market. The playbook is deliberately unglamorous—and easy to copy.

The story began with a casual conversation. Steijn Pelle had moved from Amsterdam to San Francisco and worked as an early product manager at Robinhood. One day, his own dentist explained how the practice operated. Pelle was stunned: the dentist and his team spent 200 hours every month on administrative paperwork.

That is a full-time employee doing nothing but paperwork for an entire month—2,400 hours a year.

Nor was this an isolated case. Roughly 500,000 medical practices across the US face the same problem. Each spends about $200,000 a year on administrative roles that owners struggle to fill, much less retain.

After leaving Robinhood, Pelle took a real nine-to-five job for several months—first at a dental practice in Menlo Park, then at a gastroenterology practice in Scranton.

He compared himself to Jim Halpert from The Office. A typical day began by downloading a huge PDF from an insurer's website containing hundreds of payments. He would spend the next several hours entering every payment into the practice management system. Then he would print a 40-page list of hundreds of patients the system said were due for billing, check each balance, and generate the bills one by one.

Four photos from the practices: a filing cabinet labeled E.O.B.s, a dentist holding insurance mail, and the two founders working in a hallway and back room

Four photos from their time working in the practices. The filing-cabinet drawer on the far left is labeled "E.O.B.s" and is packed with Explanation of Benefits documents from insurers. The second image shows a dentist holding a stack of letters from Cigna. Image: a16z News.

How it works

Matching payments to insurance claims takes 200 hours a month

"Administrative paperwork" is too vague to explain what the AI actually took over. Money moves through a US dental practice along the path below. Pelle's account only sketches the beginning; we reconstructed the full workflow from public sources.

Practice management system (PMS)

The practice's core system. It serves as both the clinical record and the ledger, tracking who received care, which procedures were performed, how much was paid, and what remains outstanding.

Insurance claim

After treating a patient, the practice submits a request for payment to the insurer, listing the procedures performed and the amount owed under the contract.

Claims clearinghouse

An intermediary between practices and insurers. It converts claims from each practice's format into the format each insurer accepts. Think of the clearing layer behind interbank transfers: when the two sides do not speak the same language, someone has to translate.

Electronic funds transfer (EFT)

The insurer deposits money directly into the practice's bank account, replacing the paper checks traditionally sent by mail.

Explanation of Benefits (EOB) / Electronic Remittance Advice (ERA)

An EOB explains coverage and payment to the patient. An ERA is the electronic payment detail an insurer sends to the practice, showing which patients and procedures a payment covers, how much was paid, and what was denied. The drawer labeled "E.O.B.s" in the photo above held these records.

Here is how a dental bill moves through that system:

1

The patient receives care, and the practice records each procedure in its PMS

Fillings, extractions, and X-rays each have a code and a price

2

The practice submits an insurance claim through a claims clearinghouse

The clearinghouse converts it into the insurer's accepted format

3

The insurer reviews the claim, pays, and sends payment details

Payment arrives by EFT or paper check; the EOB or ERA explains what was paid or denied

4

The incoming payment is matched to the claims originally submitted

Each reconciled item is then posted back to the PMS

Manual bottleneck
5

If insurance pays only part, the remainder is calculated and billed to the patient

That 40-page list was produced at this stage

6

Denied and underpaid claims are identified and appealed individually

Missed claims become lost revenue

Also manual

The payment workflow at a US dental practice, reconstructed from public sources. Step 4 consumes most of those 200 hours. Step 6 is where revenue can disappear outright.

Most of those "200 hours of administrative work" are spent manually matching payments to insurance claims.

After speaking with hundreds of small-business owners, Pelle was struck by how similar they were. First, most were reluctant operators. Doctors want to treat patients, plumbers want to fix toilets, and nail technicians want to do nails. Paperwork is the last thing they want to touch, but if nobody else can do it, they have to. Second, every small business relies on the same basic tasks: enter data into a system, move data between systems, communicate with customers, and complete transactions.

He offered a specific example: Dr. Ed Zuckerberg, Mark Zuckerberg's father, who opened a dental practice in Dobbs Ferry, New York. After a full day at work, dinner with his family, and putting the children to bed, he would still go downstairs to his home office at 11 p.m. to handle paperwork.

Software has not eliminated this work. It has merely rearranged it. You get a dashboard, a queue, a form, and perhaps a better place to click. But someone still has to click.

Steijn Pelle · a16z News · 2026-06-03

AI changes that. For the first time, software can understand messy context, operate across systems, and finish the job. So the founders asked whether they could build software that lets a small business run itself.

The data

Half of AI agent activity is software engineering. Healthcare accounts for just 1%

If AI is already so capable, why are humans still typing in every payment? Public data offers an answer. In February 2026, Anthropic analyzed nearly 1 million agent tool calls on its API and classified them by industry.

Share of agent tool calls (%) · Sample: 998,481

Software engineering
49.7
Back-office automation
9.1
Other
7.1
Marketing and copy
4.4
Sales and CRM
4.3
Finance and accounting
4.0
Data analysis
3.5
Academic research
2.8
Cybersecurity
2.4
Customer support
2.2
Games and media
2.1
Documents and slides
1.9
Education and tutoring
1.8
E-commerce operations
1.3
Healthcare
1.0
Legal
0.9
Travel and logistics
0.8

Data from Figure 6 of Anthropic's Measuring Agent Autonomy, published in February 2026. The metric is agent tool calls made through Anthropic's public API. We redrew the original chart without changing any values.

Half of all agent activity is software engineering. The other half is spread across 16 industries, none above 9%. Healthcare accounts for 1.0%; legal work, 0.9%.

Those small numbers are easy to misread. They point to markets that have barely been tapped. Healthcare AI is still in its infancy.

Anthropic offered a more practical explanation in a footnote to the study. Software moved first because code is easy to verify: run it, and you can see whether it works. Errors are also easier to detect. In law, healthcare, and finance, checking whether an agent performed correctly often requires as much professional expertise as doing the work itself. Trust therefore takes much longer to build.

The obstacles

Dental practices rely on dozens of systems that fail without warning

If the market is so open, why has nobody solved it? Pelle identifies three barriers. The second is the most concrete.

First: "mostly right" is not good enough

Owners must trust that claims were filed correctly, patient messages were accurate, and insurer responses were properly posted. Every entry involves money and regulated, sensitive medical information.

Second: it must handle dozens of temperamental external systems at once

A dental practice connects to dozens of insurer portals, several claims clearinghouses, a practice management system, and a bank account. There is no shared standard or central coordinator.

Each works differently—and fails without warning.

Steijn Pelle · a16z News · 2026-06-03
Insurer portal A Insurer portal B Insurer portal C Dozens more... ✕ ✕ One dental practice 2–3 people run it all ✕ Claims clearinghouse Practice system Bank account Patient billing Dark lines = fragile connections; ✕ = failures nobody reports

Illustration by this site. Taking over a practice's collections means supporting every system in this ring, even though each connection fails at a different time.

Third: even if you build it, reaching these owners is hard

Anyone who has sold to small businesses knows how difficult these owners are to reach and how little time they have. They spend their days and nights handling customers and paperwork. Even when you reach them, they are not technical users. Setup must be fast and the payoff immediate, or owners will not try the product, let alone use it daily.

The founders had relevant experience. At Robinhood, Pelle's team worked obsessively to eliminate nearly all manual review from account opening, becoming one of the first brokerages to do it. His co-founder, Frédéric Renken, was the first product hire at Superhuman, where the team scrutinized every point of friction in a new user's first experience.

What they did

Their unglamorous playbook: do the job, then install the product in person

How did they make it work? The answer has little to do with models. They embraced two labor-intensive tactics Silicon Valley had long dismissed. Both can be traced to essays Paul Graham wrote more than a decade ago.

The usual approach

Hire consultants or interview owners over coffee

In 2012, Paul Graham wrote about the Yiddish word schlep: exhausting, tedious work nobody wants to do. His observation was that the best startup ideas are often hiding in plain sight. The drudgery makes founders overlook them before they even register. He called this schlep blindness. Stripe is the classic example. Everyone knew online payments were painful, yet founders kept building recipe websites instead.

Their approach

Work inside practices for months and do the job themselves

They reconciled millions of dollars in insurance payments, submitted thousands of insurance claims, and billed hundreds of patients. They did it for months, not a weekend. That experience showed them exactly which actions consumed those 200 hours—and gave them the confidence to claim their product was an order of magnitude better than alternatives.

The usual approach

"Great, I'll send you a link"

In Do Things that Don't Scale, Paul Graham described a Stripe tactic known inside YC as the Collison installation. Other founders would ask, "Would you like to try our beta?" If the answer was yes, they would promise to send a link. The Collison brothers did not wait. They said, "Give me your laptop," and installed it on the spot.

Their approach

Fly out and install it for the first 100 practices

From Florida to Kansas to Oregon, they stood behind owners and watched them connect their practice management systems, bank accounts, and data sources one by one. Only after setting up the first 100 practices could they make the process self-service.

Lassie's two co-founders in an office with a stack of paper documents on the desk

Lassie's two co-founders. The stack of papers on the windowsill and the forms spread across the desk are the materials they handled every day for months. Image: a16z News.

Where it stands

700 practices, 49 states, and $10 million in annualized revenue

What did those two unglamorous methods produce? As of June 3, 2026, the company reported these figures.

700 practices
Using Lassie across 49 states
$10 million
Annualized revenue
30 hours
Average monthly labor saved per practice; up to 190 hours
250,000
Total customer hours saved per year

The last two figures cross-check: 250,000 hours ÷ 700 practices ÷ 12 months ≈ 29.8 hours per practice per month, matching the stated average of 30 hours. Growth has come mainly from word of mouth and customer referrals, adding dozens of practices each month. One customer told them, "You saved my marriage."

The $35 million Series A was led by a16z's Alex Rampell and Olivia Moore. The announcement puts the market at roughly 160,000 dental practices in the US. Pelle uses a broader figure of 500,000 medical practices in his account.

Today, the product automates two steps in the payment flow

Lassie's product page lists three functions. Their position in the earlier payment flow is straightforward.

1 · Enrolls electronic payments

Lassie enrolls the practice in insurers' electronic-payment systems, removing paper checks and postal delays.

2 · Reconciles EFTs

It matches every electronic funds transfer in the bank account to the correct insurer, patient, and insurance claim.

3 · Posts payments

It posts each reconciled item back to the practice management system, keeping the ledger current.

The two highlighted steps are automated today

Record care

1

Submit claim

2

Insurer pays

3

Reconcile

4

Bill patient

5

Appeal denial

6

The investment announcement also says Lassie reads insurance claims and flags those that require action—the first half of step 6. "Let small businesses run themselves" is the long-term goal. Reconciling and posting insurance payments for dental practices is the product's current scope.

a16z describes it the same way. Dental is the first market because the pain is acute, the workflow is structured and repetitive, and the dollar amounts are meaningful. The larger ambition extends beyond dentistry, but that comes later.

Two nearby figures can look like the same claim

Pelle says the system aims to replace "$200,000 a year in administrative labor." The actual result reported in the same article is an average of 30 hours recovered per practice each month.

Placed side by side, those figures can make it sound as though the full $200,000 has already been saved. At typical US wage rates for dental administrative staff, 30 hours a month represents several hundred to roughly $1,000 in monthly labor costs—or several thousand to a little over $10,000 a year. $200,000 is the ceiling for the whole category of work. 30 hours is how far the product has reached today. There is still a large gap between them.

One more calculation: $10 million in annualized revenue ÷ 700 practices ≈ $14,300 per practice per year, or roughly $1,190 per month. This is our back-of-the-envelope estimate from two public figures, not an official price. Lassie has not published pricing, and actual rates may vary by practice size.

Two issues go unmentioned throughout Pelle's account: who is liable when the AI files an insurance claim incorrectly, and how the system meets HIPAA requirements for patient data. For a product that directly handles medical billing and patient information, these are the two most important unanswered questions. The article says only that the work must be done correctly, and we found no public answers.

The business

What customers pay for is not quite what the founder pitches

Behind the headline numbers, the real reason customers pay is slightly different. You can see it only by comparing Pelle's account with the investment announcement published the same day. Each identifies a different primary benefit.

The founder's pitch

Give doctors their evenings back

"Doctors can see twice as many patients, get home on time, and actually take vacations." This version centers on time and quality of life. Its examples are Dr. Ed Zuckerberg doing paperwork at 11 p.m. and the customer who said, "You saved my marriage."

What customers told investors

Recover money that used to slip away

According to a16z, customers said the biggest benefit was recovering underpayments, denials, and missed insurance claims that previously slipped through. That mattered more than completing the work faster. It maps to step 6 in the payment flow: claims nobody identified used to become lost revenue.

Saving time is a feeling. Recovering lost money appears on the ledger. The first makes owners happy; the second gives them a measurable reason to renew every month.

The same announcement draws a hard line around the product: Lassie is not a copilot. A copilot would create more work for practice staff to review. Lassie's goal is to finish the job directly.

What to copy

Five tactics from this case are directly reusable

Set Lassie itself aside. What remains useful about its approach? Each of the five lessons below follows from the evidence above—not from a vague claim that "vertical AI has potential."

1 · Do the job for several months; do not merely research it

Research tells you there is "too much paperwork." Doing the work tells you the bottlenecks are steps 4 and 6. The founders reconciled millions of dollars in payments, submitted thousands of insurance claims, and billed hundreds of patients before they understood exactly which actions consumed those 200 hours. That level of detail determines where the product should enter the workflow. Ask yourself: have I personally run this industry's process from beginning to end?

2 · Choose the drudgery others avoid, then filter industries with four tests

Paul Graham's idea of schlep blindness has a practical implication: the less anyone wants to touch a problem, the less competition it attracts—and the harder a solution becomes to copy once built. Anthropic's distribution chart can serve as a map of markets where few people are working. To choose among them, use a16z's four reasons for selecting dental: acute pain, structured workflows, repetitive actions, and meaningful transaction values.

3 · After delivery, the customer's task list should get shorter

a16z positions Lassie as something other than a copilot because a copilot creates more work for the practice to review. This is a direct test for your own product: after installation, does the user have one less job to do, or one more dashboard to monitor? The former can replace labor budget. The latter belongs in the tools budget.

4 · Install the first 100 customers by hand; what you are installing is your own understanding

They pushed Stripe's tactic to the limit, installing the product practice by practice from Florida to Kansas to Oregon. The return was not the revenue from those 100 customers. It was learning exactly where a nontechnical user gets stuck, so customer 101 could connect the system alone. Self-service grows out of hands-on service.

5 · Ask customers how they describe you to other people

The founder says Lassie gives doctors their evenings back. Customers tell investors it recovers money they used to miss. Both are true, but only the latter is a measurable financial result—and a reason to renew every month. Once a product has traction, the words customers use to describe it are often more valuable than the positioning copy the company writes for itself.

What happened next

The saved time did not turn into layoffs

One obvious question remains: what happens to administrative staff after dozens of hours of work disappear?

Pelle invokes an old economic idea: the lump of labour fallacy. It describes the mistaken belief that the total amount of work in the world is fixed, so every additional task performed by a machine must remove one from a person.

After observing 700 practices, he says he is convinced this is a fallacy. Owners used the time to expand their practices, improve the patient experience, and do work that had always been more valuable. That is the company's account, unsupported by independent data, though it points in the same direction as another public study.

Related on this site
AI is advancing rapidly. Why hasn't US unemployment risen? Anthropic's head of economic research explains
An independent case for the same distinction: eliminating tasks is not the same as eliminating jobs.

Lassie says its next two jobs are spreading the message faster—millions of owners still do not know this is possible—and making installation simple enough for any owner to complete alone. After that comes going deeper: doing more work and connecting to more of the tools a business already uses.

Pelle's account ends with a hiring pitch.

A note on the figures: the 700-practice count cited here is from June 3, 2026. At publication, Lassie's homepage said "2,500+ doctors," while its company page still said "700+ practices." Doctors and practices are different units—a practice typically has several doctors—so the two figures cannot be compared directly.

Source
Small Businesses are the Next Frontier for AISteijn Pelle·a16z News·2026-06-03
Editorial note
The two photos come from a16z News. We drew the six-step payment workflow and external-systems diagram from public information. The industry-distribution values come from Figure 6 of Anthropic's Measuring Agent Autonomy; we redrew the original chart without changing the values. The estimated monthly price of about $1,190 per practice is our back-of-the-envelope calculation from public figures, not official pricing.
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